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CLEVELAND (AP) - Hillary Clinton triumphed Tuesday in the Florida, Ohio and North Carolina presidential primaries, putting her in a commanding position to become the first woman in U.S. history to win a major party nomination. But the contests brought little clarity to the Republican race, with Donald Trump winning big in Florida but falling in Ohio to the state's governor, John Kasich. SEE RESULTS

Florida Sen. Marco Rubio ended his once-promising campaign after his devastating home-state loss, so the GOP primary is now down to three candidates: Trump, Kasich and Texas Sen. Ted Cruz, who was hoping for wins in Missouri and Illinois. It is far from clear if any can reach the 1,237 delegates needed to clinch the GOP nomination, ratcheting up the prospects of a contested convention. RELATED: Rubio drops out

"The campaign goes on," Kasich declared at a victory rally. Now thrust into the center of a campaign that has been bitingly personal, Kasich vowed to "not take the low road to the highest office in the land."

A confident Clinton pivoted quickly to November during her victory rally, assailing Trump's hardline immigration positions and support for torture. "Our commander-in-chief has to be able to defend our country, not embarrass it," she declared.

Underscoring Republican concerns about Trump, Rubio focused heavily on an implicit critique of Trump in a speech announcing he was dropping out of the race. The senator urged Americans to "not give in to the fear, do not give in to the frustration."

A favorite of Republican leaders, Rubio is the latest candidate to fall victim to an unpredictable election cycle and Trump's unmatched ability to tap into the public's anger with Washington and frustration with sweeping economic changes.

Clinton's victories in Ohio and Florida bolstered her argument that she's the best Democratic candidate to take on the eventual Republican nominee in the general election. Her win in Ohio was a particular relief for her campaign, which grew anxious after rival Bernie Sanders pulled off a surprising win last week in Michigan, another important Midwestern state.

Clinton kept up her large margins with black voters, a crucial group for Democrats in the general election. Democratic voters were more likely to describe Sanders as honest, but more likely to describe Clinton's policies as realistic, according to exit polls.

Campaigning Tuesday in North Carolina, Clinton said "the numbers are adding up in my favor." She signaled an eagerness to move on to a possible general election showdown with Trump, saying he's laid out a "really dangerous path" for the country.

Votes were also being counted Tuesday in Missouri and Illinois, though races in both parties were too close to call. Trump and Cruz were in a close race in North Carolina.

Trump entered Tuesday's primaries embroiled in one of the biggest controversies of his contentious campaign. The GOP front-runner has encouraged supporters to confront protesters at his events and is now facing accusations of encouraging violence after skirmishes at a rally last week in Chicago.

The atmosphere at his events has deepened the concern over his candidacy in some Republican circles. Rubio and Kasich have suggested they might not be able to support Trump if he's the nominee, an extraordinary stance for intraparty rivals.

Trump is the only Republican candidate with a realistic path to a majority of the delegates before the convention. His closest competition so far has come from Cruz, who has kept relatively close to the businessman in the delegate count and has been urging other candidates to drop out so he can take Trump on one-on-one.

Even before Tuesday's results, a group of conservatives was planning a meeting to discuss options for stopping Trump, including at a contested convention or by rallying around a third-party candidate. While such no candidate has been identified, the participants in Tuesday's meeting planned to discuss ballot access issues, including using an existing third party as a vehicle or securing signatures for an independent bid.

A person familiar with the planning confirmed the meeting on the condition of anonymity because they were not authorized to discuss the gathering by name.

Despite concerns from party leaders, Republican voters continue to back Trump's most controversial proposals, with two-thirds of those who participated in GOP primaries Tuesday saying they support temporarily banning Muslims from the United States.

The exit polls were conducted by Edison Research for The Associated Press and television networks.

Trump's Florida victory brought his delegate total to 568. Cruz has 370 delegates, and Kasich with 129. Rubio left the race with 163 delegates. It takes 1,237 to win the GOP nomination.

Clinton has at least 1,483 delegates, including the superdelegates who are elected officials and party leaders free to support the candidate of their choice. Sanders has at least 682. It takes 2,383 to win the Democratic nomination.